Slaughter and May has won a role advising a coalition of media organisations opposed to NewsCorp chief Rupert Murdoch's bid to secure a full takeover of BSkyB.

Slaughters' competition team is advising eight media rivals – which include the BBC, Channel 4, The Guardian and The Daily Telegraph – on NewsCorp's bid to acquire the remaining 60.1% of shares in satellite broadcaster BSkyB, a deal which values the company at more than £12bn.

The bid has raised concerns about the level of NewsCorp's influence in the media sphere, with BBC director general Mark Thompson stating that a deal could lead to a "significant loss of plurality in the media market".

The eight signatories have lobbied the UK Government to intervene as well as calling for Ofcom to vet the deal.

On Monday (13 October) the group sent a letter to Business Secretary Vince Cable asking him to refer the proposed acquisition to the telecoms regulator.

A Channel 4 spokesperson commented: "The proposed NewsCorp purchase of the equity it does not already own in BSkyB is of such significance that Channel 4 believes it should be looked at by Ofcom."

Skadden London corporate partners Michael Hatchard and John Adebiyi, alongside New York M&A partners Lou Kling and Howard Ellin, are advising NewsCorp, which owns The Sun, The Times and News of the World newspapers and has a market capitalisation of around $35bn (£24bn).

Allen & Overy is advising NewsCorp on UK corporate law with a team led by City corporate partner Don McGown.

Herbert Smith corporate partners Stephen Wilkinson, Malcolm Lombers and James Milne are leading the firm's team advising BSkyB, with support from competition partner Elizabeth McKnight and US partner Jim Wickenden.

It is understood that Cleary Gottlieb Steen & Hamilton and Hogan Lovells are advising NewsCorp on competition approvals, while Bird & Bird is also thought to have a role on the deal.